Global health burden and cost of lead exposure in children and adults: a health impact and economic modelling analysis

Evidence of turmeric adulteration with lead chromate across South Asia

Food adulteration with toxic chemicals is a global public health threat. Lead chromate adulterated spices have been linked with lead poisoning in many countries, from Bangladesh to the United States. This study systematically assessed lead chromate adulteration in turmeric, a spice that is consumed daily across South Asia. Our study focused on four understudied countries that produce >80 % of the world's turmeric and collectively include 1.7 billion people, 22 % of the world's population. Turmeric samples were collected from wholesale and retail bazaars from 23 major cities across India, Pakistan, Sri Lanka, and Nepal between December 2020 and March 2021. Turmeric samples were analyzed for lead and chromium concentrations and maximum child blood lead levels were modeled in regions where samples had detectable lead. A total of 356 turmeric samples were collected, including 180 samples of dried turmeric roots and 176 samples of turmeric powder. In total, 14 % of the samples (n = 51) had detectable lead above 2 μg/g. Turmeric samples with lead levels greater than or equal to 18 μg/g had molar ratios of lead to chromium near 1:1, suggestive of lead chromate adulteration. Turmeric lead levels exceeded 1000 μg/g in Patna (Bihar, India) as well as Karachi and Peshawar (Pakistan), resulting in projected child blood lead levels up to 10 times higher than the CDC's threshold of concern. Given the overwhelmingly elevated lead levels in turmeric from these locations, urgent action is needed to halt the practice of lead chromate addition in the turmeric supply chain.

Potential mechanisms of aortic medial degeneration promoted by co-exposure to microplastics and lead

Microplastics (MPs) have attracted widespread attention because they can lead to combined toxicity by adsorbing heavy metals from the environment. Exposure to lead (Pb), a frequently adsorbed heavy metal by MPs, is common. In the current study, the coexistence of MPs and Pb was assessed in human samples. Then, mice were used as models to examine how co-exposure to MPs and Pb promotes aortic medial degeneration. The results showed that MPs and Pb co-exposure were detected in patients with aortic disease. In mice, MPs and Pb co-exposure promoted the damage of elastic fibers, loss of vascular smooth muscle cells (VSMCs), and release of inflammatory factors. In vitro cell models revealed that co-exposure to MPs and Pb induced excessive reactive oxygen species generation, impaired mitochondrial function, and triggered PANoptosome assembly in VSMCs. These events led to PANoptosis and inflammation through the cAMP/PKA-ROS signaling pathway. However, the use of the PKA activator 8-Br-cAMP or mitochondrial ROS scavenger Mito-TEMPO improved, mitochondrial function in VSMCs, reduced cell death, and inhibited inflammatory factor release. Taken together, the present study provided novel insights into the combined toxicity of MPs and Pb co-exposure on the aorta.

Edetate Disodium-Based Chelation for Patients With a Previous Myocardial Infarction and Diabetes: TACT2 Randomized Clinical Trial

Importance

In 2013, the Trial to Assess Chelation Therapy (TACT) reported that edetate disodium (EDTA)-based chelation significantly reduced cardiovascular disease (CVD) events by 18% in 1708 patients with a prior myocardial infarction (MI).

Objective

To replicate the finding of TACT in individuals with diabetes and previous MI.

Design, Setting, and Participants

A 2 × 2 factorial, double-masked, placebo-controlled, multicenter trial at 88 sites in the US and Canada, involving participants who were 50 years or older, had diabetes, and had experienced an MI at least 6 weeks before recruitment compared the effect of EDTA-based chelation vs placebo infusions on CVD events and compared the effect of high doses of oral multivitamins and minerals with oral placebo. This article reports on the chelation vs placebo infusion comparisons.

Interventions

Eligible participants were randomly assigned to 40 weekly infusions of an EDTA-based chelation solution or matching placebo and to twice daily oral, high-dose multivitamin and mineral supplements or matching placebo for 60 months. This article addresses the chelation study.

Main Outcomes and Measures

The primary end point was the composite of all-cause mortality, MI, stroke, coronary revascularization, or hospitalization for unstable angina. Median follow-up was 48 months. Primary comparisons were made from patients who received at least 1 assigned infusion.

Results

Of the 959 participants (median age, 67 years [IQR, 60-72 years]; 27% females; 78% White, 10% Black, and 20% Hispanic), 483 received at least 1 chelation infusion and 476 at least 1 placebo infusion. A primary end point event occurred in 172 participants (35.6%) in the chelation group and in 170 (35.7%) in the placebo group (adjusted hazard ratio [HR], 0.93; 95% CI, 0.76-1.16; P = .53). The 5-year primary event cumulative incidence rates were 45.8% for the chelation group and 46.5% for the placebo group. CV death, MI, or stroke events occurred in 89 participants (18.4%) in the chelation group and in 94 (19.7%) in the placebo group (adjusted HR, 0.89; 95% CI, 0.66-1.19). Death from any cause occurred in 84 participants (17.4%) in the chelation group and in 84 (17.6%) in the placebo group (adjusted HR, 0.96; 95% CI, 0.71-1.30). Chelation reduced median blood lead levels from 9.03 μg/L at baseline to 3.46 μg/L at infusion 40 (P < .001). Corresponding levels in the placebo group were 9.3 μg/L and 8.7 μg/L, respectively.

Conclusions and Relevance

Despite effectively reducing blood lead levels, EDTA chelation was not effective in reducing cardiovascular events in stable patients with coronary artery disease who have diabetes and a history of MI.

Trial Registration

ClinicalTrials.gov Identifier: NCT02733185.

Nucleic acid aptamers protect against lead (Pb(II)) toxicity

Lead (Pb(II)) is a pervasive heavy metal toxin with many well-established negative effects on human health. Lead toxicity arises from cumulative, repeated environmental exposures. Thus, prophylactic strategies to protect against the bioaccumulation of lead could reduce lead-associated human pathologies. Here we show that DNA and RNA aptamers protect C. elegans from toxic phenotypes caused by lead. Reproductive toxicity, as measured by brood size assays, is prevented by co-feeding of animals with DNA or RNA aptamers. Similarly, lead-induced neurotoxicity, measured by behavioral assays, are also normalized by aptamer feeding. Further, cultured human HEK293 and primary murine osteoblasts are protected from lead toxicity by transfection with DNA aptamers. The osteogenic development, which is decreased by lead exposure, is maintained by prior transfection of lead-binding DNA aptamers. Aptamers may be an effective strategy for the protection of human health in the face of increasing environmental toxicants.

Structured expert judgement approach of the health impact of various chemicals and classes of chemicals

INTRODUCTION

Chemical contamination and pollution are an ongoing threat to human health and the environment. The concern over the consequences of chemical exposures at the global level continues to grow. Because resources are constrained, there is a need to prioritize interventions focused on the greatest health impact. Data, especially related to chemical exposures, are rarely available for most substances of concern, and alternate methods to evaluate their impact are needed.

STRUCTURED EXPERT JUDGMENT (SEJ) PROCESS

A Structured Expert Judgment (Research Outreach, 2021) process was performed to provide plausible estimates of health impacts for 16 commonly found pollutants: asbestos, arsenic, benzene, chromium, cadmium, dioxins, fluoride, highly hazardous pesticides (HHPs), lead, mercury, polycyclic-aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), Per- and Polyfluorinated Substances (PFAs), phthalates, endocrine disrupting chemicals (EDCs), and brominated flame retardants (BRFs). This process, undertaken by sector experts, weighed individual estimations of the probable global health scale health impacts of each pollutant using objective estimates of the expert opinions' statistical accuracy and informativeness.

MAIN FINDINGS

The foremost substances, in terms of mean projected annual total deaths, were lead, asbestos, arsenic, and HHPs. Lead surpasses the others by a large margin, with an estimated median value of 1.7 million deaths annually. The three other substances averaged between 136,000 and 274,000 deaths per year. Of the 12 other chemicals evaluated, none reached an estimated annual death count exceeding 100,000. These findings underscore the importance of prioritizing available resources on reducing and remediating the impacts of these key pollutants.

RANGE OF HEALTH IMPACTS

Based on the evidence available, experts concluded some of the more notorious chemical pollutants, such as PCBs and dioxin, do not result in high levels of human health impact from a global scale perspective. However, the chemical toxicity of some compounds released in recent decades, such as Endocrine Disrupters and PFAs, cannot be ignored, even if current impacts are limited. Moreover, the impact of some chemicals may be disproportionately large in some geographic areas. Continued research and monitoring are essential; and a preventative approach is needed for chemicals.

FUTURE DIRECTIONS

These results, and potential similar analyses of other chemicals, are provided as inputs to ongoing discussions about priority setting for global chemicals and pollution management. Furthermore, we suggest that this SEJ process be repeated periodically as new information becomes available.

Estimating lead-attributable mortality burden by socioeconomic status in the USA

BACKGROUND

This study aimed to estimate population-level and state-level lead-attributable mortality burdens stratified by socioeconomic status (SES) class in the USA.

METHODS

Based on the National Health and Nutrition Examination Survey (NHANES), we constructed individual-level SES scores from income, employment, education and insurance data. We assessed the association between the blood lead levels (BLL) and all-cause mortality by Cox regression in the NHANES cohort (n = 31 311, 4467 deaths). With estimated hazard ratios (HR) and prevalences of medium (2-5 μg/dL) and high (≥ 5 μg/dL) BLL, we computed SES-stratified population-attributable fractions (PAFs) of all-cause mortality from lead exposure across 1999-2019. We additionally conducted a systematic review to estimate the lead-attributable mortality burden at state-level.

RESULTS

The HR for every 2-fold increase in the BLL decreased from 1.23 (1.10-1.38) for the lowest SES class to 1.05 (0.90-1.23) for the highest SES class. Across all SES quintiles, medium BLL exhibited a greater mortality burden. Individuals with lower SES had higher lead-attributable burdens, and such disparities haver persisted over the past two decades. In 2017-19, annually 67 000 (32 000-112 000) deaths in the USA were attributable to lead exposure, with 18 000 (2000-41 000) of these deaths occurring in the lowest SES class. Substantial disparities in the state-level mortality burden attributable to lead exposure were also highlighted.

CONCLUSIONS

These findings suggested that disparities in lead-attributable mortality burden persisted within US adults, due to heterogeneities in the effect sizes of lead exposure as well as in the BLL among different SES classes.

Water, Soil, Noise, and Light Pollution: JACC Focus Seminar, Part 2

Various forms of pollution carry a substantial burden with respect to increasing the risk of causing and exacerbating noncommunicable diseases, especially cardiovascular disease. The first part of this 2-part series on pollution and cardiovascular disease provided an overview of the impact of global warming and air pollution. This second paper provides an overview of the impact of water, soil, noise, and light pollution on the cardiovascular system. This review discusses the biological mechanisms underlying these effects and potential environmental biometrics of exposure. What is clear from both these pollution papers is that significant efforts and redoubled urgency are needed to reduce the sources of pollution in our environment, to incorporate environmental risk factors into medical education, to provide resources for research, and, ultimately, to protect those who are particularly vulnerable and susceptible.

Cottage industry as a source of high exposure to lead: A biomonitoring study among people involved in manufacturing cookware from scrap metal

In low-income countries, a widespread but poorly studied type of cottage industry consists of melting scrap metal for making cookware. We assessed the exposure to lead (Pb) among artisanal workers, and their families, involved in manufacturing cookware from scrap metal. In a cross-sectional survey, we compared artisanal cookware manufacturing foundries with carpentry workshops (negative controls) and car battery repair workshops (positive controls), all located in residential areas, in Lubumbashi (DR Congo). We collected surface dust in the workspaces, and blood and urine samples among workers, as well as residents living in the cookware workshops. Trace elements were quantified in the samples by Inductively Coupled Plasma Mass Spectrometry (ICP-MS). In surface dust, median Pb concentrations were higher in cookware foundries (347 mg/kg) than in carpentries (234 mg/kg) but lower than in battery repair workshops (22,000 mg/kg). In workers making the cookware (n = 24), geometric mean (GM) Pb blood cencentration was 118 μg/L [interquartile range (IQR) 78.4-204], i.e. nearly twice as high as among carpenters [60.2 μg/L (44.4-84.7), n = 33], and half the concentration of battery repair workers [255 μg/L (197-362), n = 23]. Resident children from the cookware foundries, had higher urinary Pb [6.2 μg/g creatinine (2.3-19.3), n = 6] than adults [2.3 (2.2-2.5), n = 3]. Our investigation confirms the high Pb hazard linked to car battery repair and reveals a high exposure to Pb among artisanal cookware manufacturers and their families, especially children, in residential areas of a city in a low-income country.

Evaluating metal cookware as a source of lead exposure

BACKGROUND

We previously demonstrated that aluminum cookware brought from Afghanistan by resettled families as well as some aluminum cookware available for purchase in the United States represent a previously unrecognized source of lead exposure. However, the extent to which this cookware represents a source of lead exposure to other United States residents is unclear.

OBJECTIVES

To test additional cookware for lead content and its propensity to leach lead and other toxic metals. This will further our understanding of the extent to which this cookware represents a lead poisoning risk in the United States and elsewhere.

METHODS

We screened an additional 28 pieces of aluminum cookware and 5 brass items for lead content using an X-ray fluorescence (XRF) analyzer and used our leachate method to estimate the amount of lead that migrates into food. We also tested 17 additional stainless steel items to determine whether they would be safer alternatives.

RESULTS

Many aluminum cookware products contained in excess of 100 parts per million (ppm) of lead. Many also leached enough lead under simulated cooking and storage conditions to exceed recommended dietary limits. One hindalium appam pan (an Indian frying pan/wok) leached sufficient lead to exceed the childhood limit by 1400-fold. Brass cookpots from India also yielded high lead levels, with one exceeding the childhood limit by over 1200-fold. In contrast, stainless steel cookware leached much lower levels of lead.

IMPACT

Aluminum and brass cookware available for purchase in the United States represents a previously unrecognized source of lead exposure.

Biomarkers of metal exposure in adolescent e-cigarette users: correlations with vaping frequency and flavouring

BACKGROUND

Youth vaping poses a significant public health concern as metals have been detected in e-cigarette aerosols and liquids. This study investigated factors associated with biomarkers of metal exposure.

METHODS

Data were drawn from Wave 5 of the Population Assessment of Tobacco and Health (PATH) Study Youth Panel, a nationally representative sample of US adolescents aged 13-17 years. Urinary biomarkers of exposure to cadmium, lead, and uranium were assessed by vaping frequency (occasional (1-5 days), intermittent (6-19 days), and frequent (20+ days)) in the past 30 days and flavour type (menthol/mint, fruit, and sweet).

RESULTS

Among 200 exclusive e-cigarette users (median age 15.9 years, 62.9% female), 65 reported occasional use, 45 reported intermittent use, and 81 reported frequent use. The average number of recent puffs per day increased exponentially by vaping frequency (occasional: 0.9 puffs, intermittent: 7.9 puffs, frequent: 27.0 puffs; p=0.001). Both intermittent (0.21 ng/mg creatinine) and frequent users (0.20 ng/mg creatinine) had higher urine lead levels than occasional users (0.16 ng/mg creatinine). Frequent users also had higher urine uranium levels compared with occasional users (0.009 vs 0.005 ng/mg creatinine, p=0.0004). Overall, 33.0% of users preferred using menthol/mint flavours, 49.8% fruit flavours, and 15.3% sweet flavours. Sweet flavour users had higher uranium levels compared with menthol/mint users (0.009 vs 0.005 ng/mg creatinine, p=0.02).

CONCLUSIONS

Vaping in early life could increase the risk of exposure to metals, potentially harming brain and organ development. Regulations on vaping should safeguard the youth population against addiction and exposure to metals.

Environmental Impacts on Cardiovascular Health and Biology: An Overview

Environmental stressors associated with human activities (eg, air and noise pollution, light disturbance at night) and climate change (eg, heat, wildfires, extreme weather events) are increasingly recognized as contributing to cardiovascular morbidity and mortality. These harmful exposures have been shown to elicit changes in stress responses, circadian rhythms, immune cell activation, and oxidative stress, as well as traditional cardiovascular risk factors (eg, hypertension, diabetes, obesity) that promote cardiovascular diseases. In this overview, we summarize evidence from human and animal studies of the impacts of environmental exposures and climate change on cardiovascular health. In addition, we discuss strategies to reduce the impact of environmental risk factors on current and future cardiovascular disease burden, including urban planning, personal monitoring, and mitigation measures.

Chronic lead exposure and burden of cardiovascular disease during 1990-2019: a systematic analysis of the global burden of disease study

Background

Cardiovascular diseases (CVD) are the leading causes of death and disability worldwide. Lead exposure is an important risk factor for CVD. In our study, we aimed to estimate spatial and temporal trends in the burden of cardiovascular disease associated with chronic lead exposure.

Methods

The data collected for our study were obtained from Global Burden of Disease (GBD) study 2019 and analyzed by age, sex, cause, and location. To assess the temporal trends in burden of CVD attributable to chronic lead exposure over 30 years, we used Joinpoint regression analysis.

Results

In 2019, the number of lead exposure-attributable CVD deaths and disability-adjusted life-years (DALYs) were 0.85 and 17.73 million, 1.7 and 1.4 times more than those observed in 1990, respectively. However, the corresponding age-standardized rates (ASR) of death and DALY gradually decreased from 1990 to 2019, especially from 2013 to 2019. Over the last 30 years, among 21 GBD regions and 204 countries and territories, the High-income Asia Pacific and the Republic of Korea experienced the largest reductions in age-standardized DALY and death rates, while Central Asia and Afghanistan experienced the largest increases. Males and the elderly population suffered higher death rates and DALY burdens than females and the young population. Furthermore, we observed that higher socio-demographic index (SDI) regions demonstrated lower ASR of death and DALY rates. In 2019, the low and low-middle SDI regions, especially South Asia, exhibited the highest burden of CVD attributable to lead exposure.

Conclusion

Our study provides a thorough understanding of the burden of CVD attributable to chronic lead exposure. The findings confirm the significance of implementing lead mitigation strategies and increasing investment in CVD prevention and treatment. These measures are crucial in reducing the burden of CVD and promoting public health on a global scale.

Nucleic Acid Aptamers Protect Against Lead (Pb(II)) Toxicity

Lead (Pb(II)) is a pervasive heavy metal toxin with many well-established negative effects on human health. Lead toxicity arises from cumulative, repeated environmental exposures. Thus, prophylactic strategies to protect against the bioaccumulation of lead could reduce lead-associated human pathologies. Here we show that DNA and RNA aptamers protect C. elegans from toxic phenotypes caused by lead. Reproductive toxicity, as measured by brood size assays, is prevented by co-feeding of animals with DNA or RNA aptamers. Similarly, lead-induced behavioral anomalies are also normalized by aptamer feeding. Further, cultured human HEK293 and primary murine osteoblasts are protected from lead toxicity by transfection with DNA aptamers. The osteogenic development, which is decreased by lead exposure, is maintained by prior transfection of lead-binding DNA aptamers. Aptamers may be an effective strategy for the protection of human health in the face of increasing environmental toxicants.

Advanced Integration of Glutathione-Functionalized Optical Fiber SPR Sensor for Ultra-Sensitive Detection of Lead Ions

It is crucial to detect Pb2+ accurately and rapidly. This work proposes an ultra-sensitive optical fiber surface plasmon resonance (SPR) sensor functionalized with glutathione (GSH) for label-free detection of the ultra-low Pb2+ concentration, in which the refractive index (RI) sensitivity of the multimode-singlemode-multimode (MSM) hetero-core fiber is largely enhanced by the gold nanoparticles (AuNPs)/Au film coupling SPR effect. The GSH is modified on the fiber as the sensing probe to capture and identify Pb2+ specifically. Its working principle is that the Pb2+ chemically reacts with deprotonated carboxyl groups in GSH through ligand bonding, resulting in the formation of stable and specific chelates, inducing the variation of the local RI on the sensor surface, which in turn leads to the SPR wavelength shift in the transmission spectrum. Attributing to the AuNPs, both the Au substrates can be fully functionalized with the GSH molecules as the probes, which largely increases the number of active sites for Pb2+ trapping. Combined with the SPR effect, the sensor achieves a sensitivity of 2.32 × 1011 nm/M and a limit of detection (LOD) of 0.43 pM. It also demonstrates exceptional specificity, stability, and reproducibility, making it suitable for various applications in water pollution, biomedicine, and food safety.

Direct Environmental Lead Detection by Photoluminescent Perovskite Formation with Nanogram Sensitivity

Although the global ban on leaded gasoline has markedly reduced lead poisoning, many other environmental sources of lead exposure, such as paint, pipes, mines, and recycling sites remain. Existing methods to identify these sources are either costly or unreliable. We report here a new, sensitive, and inexpensive lead detection method that relies on the formation of a perovskite semiconductor. The method only requires spraying the material of interest with methylammonium bromide and observing whether photoluminesence occurs under UV light to indicate the presence of lead. The method detects as little as 1.0 ng/mm2 of lead by the naked eye and 50 pg/mm2 using a digital photo camera. We exposed more than 50 different materials to our reagent and found no false negatives or false positives. The method readily detects lead in soil, paint, glazing, cables, glass, plastics, and dust and could be widely used for testing the environment and preventing lead poisoning.